AU768382B2

AU768382B2 - Catalytic composition for the upgrading of hydrocarbons having boiling points within the naphtha range

Info

Publication number: AU768382B2
Application number: AU22599/00A
Authority: AU
Inventors: Virginio Arrigoni; Donatella Berti; Marco Ferrari; Laura Maria Zanibelli
Original assignee: Agip Petroli SpA; Eni Tecnologie SpA
Current assignee: Agip Petroli SpA; Eni Tecnologie SpA
Priority date: 1999-05-07
Filing date: 2000-03-27
Publication date: 2003-12-11
Anticipated expiration: 2020-03-27
Also published as: MXPA00004289A; BR0002401B1; ATE459699T1; IT1312337B1; US20040222132A1; US7160439B2; CA2308736C; CN1290974C; US6908880B2; JP2000351977A; AU2259900A; NO20002376D0; EP1050571B1; CN1273266A; NO324929B1; US20030038059A1; NO20002376L; CN1200768C; RU2202597C2; EP1050571A1

Abstract

A process is described for the upgrading of hydrocarbon mixtures which boil within the naphtha range containing sulfur impurities, i.e. a hydrodesulfuration process with contemporaneous skeleton isomerization and reduced hydrogenation degree of the olefins contained in said hydrocarbon mixtures, the whole process being carried out in a single step. The process is carried out in the presence of a catalytic system comprising a metal of group VI B, a metal of group VIII and a carrier of acid nature consisting of a mesoporous silico-alumina.

Description

4 d

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: 00 Name of Applicant: EniTecnologie S.P.A. and AgipPetroli S.p.A.

Actual Inventor(s): LAURA MARIA ZANIBELLI, MARCO FERRARI, VIRGINIO ARRIGONI, DONATELLA

BERTI

Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: CATALYTIC COMPOSITION FOR THE UPGRADING OF HYDROCARBONS HAVING BOILING POINTS WITHIN THE NAPHTHA RANGE Our Ref 612813 POF Code: 356100/356100, 50742 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- 6006q CATALYTIC COMPOSITION FOR THE UPGRADING OF HYDROCARBONS HAV- ING BOILING POINTS WITHIN THE NAPHTHA RANGE.

The present invention relates to a process for the up- 10 grading of hydrocarbon mixtures which boil within the naphtha range containing sulfur impurities, i.e. a hydrodesulfuration process with contemporaneous skeleton isomerization and reduced hydrogenation degree of the olefins contained in said hydrocarbon mixtures, the whole process being carried out in a single step. The process is effected in the presence of a catalytic system comprising a metal of group VI B, a metal of group VIII and a carrier of acid nature consisting of a mesoporous silico-alumina.

This catalytic system can be used, in particular, for the upgrading of mixtures of hydrocarbons which boil within the naphtha range deriving from cracking processes, preferably mixtures of hydrocarbons having a boiling point within the naphtha range deriving from FCC catalytic cracking (Fluid Catalytic Cracking).

Hydrocarbons which boil within the naphtha.range dela riving from FCC gasoline cut) are used as blending component of gasolines. For this purpose, it is necessary for them to have a high octane number together with a low sulfur content, to conform with the law restrictions which are becoming increasingly more severe, in order to reduce the emission of contaminants. The sulfur present in gasoline mixtures in fact mainly comes from the gasoline cut deriving from FCC.

This cut is also rich in olefins which have a high oc- 10 tane number. Hydrogenation processes used for desulfuration also hydrogenate the olefins present with a consequent considerable reduction in the octane number (RON and MON). The necessity has therefore been felt for finding a catalytic system which decreases the sulfur content in hydrocarbon mixtures which boil within the naphtha range and, at the same e time, minimizes the octane loss (RON and MON), which can be achieved, for example, by the skeleton isomerization of the olefins present and/or by inhibiting the hydrogenation of the olefinic double bond.

The use of zeolites with a medium pore dimension as isomerization catalysts and the consequent recovery of octane in the charges already subjected to desulfuration are already known (US 5298150, US 5320742, US 5326462, US 5318690, US 5360532, US 5500108, US 5510016, US 5554274, US 599439). In these known processes, in order to obtain hydrodesulfuration 2 with a reduced octane loss, it is necessary to operate in two steps, using in the first step catalysts suitable for desulfuration and in the second step catalysts for recovering the octane number.

US 5.378.352 describes a process in a single step for desulfurating hydrocarbon fractions, with boiling points within the range of gasolines, using a catalyst which comprises a metal of group VIII, a metal of group VI B and a zeolite.

10 MI97A 002288 describes a catalytic system capable of isomerizing n-paraffins having a number of carbon atoms higher than 15 which comprises: o.

a) a carrier of acid nature consisting of a silica and alumina gel, amorphous to X-rays, with a molar ratio SiO 2 /A1 2 0 3 ranging from 30/1 to 500/1, having a surface area of 500 to 1000 m 2 a porosity ranging from 0.3 to 0.6 ml/g and a pore diameter within the range of 10-40 A; b) a mixture of metals belonging to groups VI B and VIII deposited on the carrier in an overall quantity of 2 to by weight with respect to the total of The acid carrier of the catalyst preferably has a ratio SiO 2 /A1 2 03 ranging from 50/1 to 300/1 and a porosity of 0.4 to ml/g.

The mixture of metals preferably consists of a metal of group VI B selected from molybdenum and tungsten, in a 3 quantity ranging from 5 to 35% by weight, and a non-noble metal of group VIII selected from nickel and cobalt, in a quantity ranging from 0.1 to 5% by weight.

The carrier based on silica and alumina gel can be conveniently prepared according to what is described in the patent US 5,049,536 or in patent application EP 659478. This carrier can be used as such for the deposition of the metal phase or in extruded form, as described for example in EP 550922 and EP 665055. The metal phase of the catalyst can 10 be introduced by means of aqueous impregnation by wetting the carrier, or extruded carrier, with an aqueous solution of a compound of a metal of group VI B, and drying the resulting product which is then impregnated with an aqueous solution of a compound of the metal of group VIII and dried again. Calcination is then carried out in an oxidating atmosphere at a temperature ranging from 200 to 600 0 C. Alternatively, a single aqueous solution containing both the compounds of the eeeo metals of groups VI B and VIII can be used for contemporaneously introducing these metals. In the case of alcohol impregnation, the acid carrier is suspended in an alcohol solution containing both compounds of the metals of groups VI B and VIII. After impregnation, the solid is dried and calcined.

These catalytic compositions are useful in the hydroisomerization of n-paraffins having a number of carbon atoms 4 higher than 15 to obtain bases for lubricating oils characterized by a low "pour point" and a high viscosity index.

It has now been surprisingly found that with the use of these catalytic compositions, optionally also containing a higher percentage of metals, it is possible to desulfurate, with high conversion values, mixtures of hydrocarbons that boil within the naphtha range containing sulfur and olefins and contemporaneously obtain the skeleton isomerization of the olefins present with a low hydrogenation degree of the 10 olefinic double bond. This catalytic system is also active at temperatures and pressures that are lower than those preferably used in the known art for hydrodesulfuration.

Both skeleton isomerization and reduced olefinic hydrogenation enable hydrocarbon mixtures to be obtained, which boil within the naphtha range with very low RON (research octane number) and MON (motor octane number) losses.

The results obtained do not only relate to the desulfuration of hydrocarbon cuts that boil within the "heavy naphtha" range (130 0 -250 0 i.e. cuts poor in olefins, but also feeds of "full range naphtha", which boil within the range of 35°-250°C, i.e. in the case of cuts rich in olefins. In fact, the process of the present invention gives a high selectivity for desulfuration with a reduced hydrogenating activity, which represents an additional advantage in terms of octane recovery in the end-gasoline.

5 A first object of the present invention therefore relates to a hydrodesulfuration process of hydrocarbon mixtures having boiling ranges within the range of C4 to 2500C, containing olefins and at least 150 ppm of sulfur, with the contemporaneous skeleton isomerization of these olefins, which comprises putting said hydrocarbon mixtures in contact, in the presence of hydrogen, with a catalytic composition comprising: a) a carrier of acid nature consisting of a silica and alumina gel, amorphous to X-rays, with a molar ratio Si02/A1203 ranging from 30/1 to 500/1, having a surface area .g ranging from 500 to 1000 m 2 a porosity ranging from 0.3 to 0.6 ml/g and a pore diameter within the range of 10-40

A;

a mixture of metals belonging to groups VI B and VIII deposited on the carrier in an overall quantity of 2 to 67% by weight with respect to the total weight of The acid carrier of the catalyst preferably has a ratio Si0 2 /A1 2 0 3 ranging from 50/1 to 300/1 and a porosity of 0.4 to ml/g.

According to a preferred aspect of the present invention, the mixture of metals consists of a metal of group VI B, preferably selected from molybdenum and tungsten, and a metal of group VIII, preferably selected from cobalt and nickel.

According to a particularly preferred aspect of the pre- 6 sent invention the mixture of metals consists of molybdenum and cobalt.

The metal of group VI B is preferably in a quantity ranging from 5 to 50% by weight with respect to the total weight of even more preferably in a quantity ranging from 8 to 30% by weight. The metal of group VIII is in a quantity ranging from 0.5 to 10% by weight with respect to the total of even more preferably in a quantity ranging from 1 to 5% by weight.

10 The weight percentages of the metal of group VI B and of the metal of group VIII refer to the metal content expressed e.

as metal element of group VI B and metal element of group VIII; in the end-catalyst, after calcination, these metals are in the form of an oxide. According to a particularly preferred aspect the molar ratio between the metal of group VIII e 4 and the metal of group VI is less than or equal to 2, preferably less than or equal to 1.

*0 The silica and alumina gel carrier can be conveniently prepared as described in US 5049536, in EP 659,478 or in EP 812804. In particular, an aqueous solution is prepared, of a tetra-alkyl ammonium hydroxide (TAA-OH), wherein alkyl is for example n-propyl or n-butyl, a soluble compound of aluminum capable of hydrolyzing in A1 2 0 3 and a soluble compound of silicon capable of hydrolyzing in SiO 2 the quantity of reagents in solution being such as to respect the following mo- 7 lar ratios: Si0 2 /A1 2 03 from 30/1 to 500/1; TAA-OH/SiO2 from 0.05/1 to 0.2/1;

H

2 0/SiO 2 from 5/1 to 40/1.

The solution thus obtained is heated to gelation, the gel obtained is dried and is calcined in an inert atmosphere and then in an oxidating atmosphere.

The acid carrier of the catalyst which is used in the process of the present invention can be used as such or 10 in the form of an extruded product with traditional ligands, such as for example aluminum oxide, bohemite or pseudobohemite. The carrier and ligand can be premixed in weight ratios ranging from 30:70 to 90:10, preferably from 50:50 to 70:30. At the end of the mixing, the product obtained is consolidated into the desired end-form, for example into the form of extruded cylinders or tablets. According to a preferred aspect the silica and alumina gel carrier can be bound with bohemite or pseudobohemite as described in EP 550,992. Even more preferably the material is used in extruded form as described in EP 665,055, consisting of an inert ligand and silica and alumina gel obtained as follows: a) preparing an aqueous solution of a tetraalkylammonium hydroxide (TAA-OH), a soluble compound of aluminum capable of hydrolyzing in A1 2 0 3 and a silicon compound capable of hydrolyzing in Si0 2 in the following molar ratios: 8 Si02/Al 2 03 from 30/1 to 500/1; TAA-OH/SiO2 from 0.05/1 to 0.2/1;

H

2 0/Si02 from 5/1 to 40/1; b) heating the solution thus obtained to cause hydrolysis and gelation and obtain a mixture A with a viscosity ranging from 0.01 to 100 Pa sec; c) adding to the mixture A first a ligand belonging to the group of bohemites or pseudobohemites, in a weight ratio with the mixture A of 0.05 to 0.5, and then a mineral or organic 10 acid in a quantity ranging from 0.5 to 8 g per 100 g of ligand; d) mixing and heating the mixture obtained under point (c) to a temperature ranging from 40° to 90 0 C until a homogeneous paste is obtained, which is subjected to extrusion; e) drying of the extruded product and calcination in an 0 oxidating atmosphere.

As far as the metal phase of the catalyst is concerned, it can be introduced by means of aqueous or alcohol impregnation. According to a first technique, the silica and alumina gel, also in extruded form, is wetted with an aqueous solution of a compound of a metal of group VI B, for example ammonium heptamolibdate, the resulting product is dried, is optionally calcined, and is then impregnated with an aqueous solution of a compound of the metal of group VIII, for example cobalt nitrate. It is then dried and calcined in an oxi- 9 dating atmosphere at a temperature ranging from 200 to 600 0

C.

Alternatively a single aqueous solution containing both compounds of the metals of groups VI B and VIII can be used for contemporaneously introducing these metals.

In the case of alcohol impregnation, the acid carrier is suspended in an alcohol solution containing both compounds of the metals of groups VI B and VIII. After impregnation the solid is dried and calcined.

The catalysts used in the present invention wherein com- 10 ponent corresponds to a mixture of metals belonging to groups VI B and VIII, preferably cobalt and molybdenum, deposited on the carrier in an overall quantity of over 50% and less than or equal to 67% by weight with respect to the total of are new and are a further object of the present invention. According to a preferred aspect these new catalytic compositions contain the metal of group VI B in a quantity greater than 45% and less than or equal to 57% by weight with respect to the total weight of and the metal of group VIII in a quantity ranging from 5 to 10% by weight with respect to the total weight of (b) A further object of the present invention also relates to a catalytic composition comprising: a) a carrier of acid nature consisting of a silica and alumina gel, amorphous to X-rays, with a molar ratio Si0 2 /A1203 ranging from 30/1 to 500/1, having a surface area ranging from 500 to 1000 m 2 a porosity ranging from 0.3 to 0.6 ml/g and a pore diameter within the range of 10-40 Amstrongs; a mixture of cobalt and molybdenum deposited on the carrier in an overall quantity of 2 to 50% by weight with respect to the total weight of the catalytic composition The process of the present invention is preferably carried out at a temperature ranging from 2200 to 360 0 C, even 10 more preferably from 2500 to 330 0 C, at a pressure ranging from 5 to 20 kg/cm 2 even more preferably from 5 to 10 kg/cm 2 o o* at a WHSV ranging from 1 to 10 hours even more preferably from 2 to 6 hours 1 The quantity of hydrogen ranges from 100 to 500 times the quantity of hydrocarbons present (N1/1), even more preferably from 200 to 400 times.

The hydrocarbon mixture which can be desulfurated according to the present invention contains more than 150 ppm 5e5 of sulfur. For example hydrocarbon mixtures with a sulfur content of more than 600 ppm, or even higher than 10000 ppm can be subjected to hydrodesulfuration.

The hydrocarbon mixtures which are subjected to hydrodesulfuration according to the process of the present invention are mixtures having boiling ranges within the range of C 4 to 250°C, wherein C 4 refers to the boiling temperature of a mixture of hydrocarbons having four carbon atoms, and hydrocar- 11 bon mixtures boiling within the naphtha range, i.e. having boiling ranges within the range of C 5 to about 220 0 C, wherein

C

5 refers to the boiling temperature of a mixture of hydrocarbons with five carbon atoms, are preferably subjected to hydrodesulfuration.

The catalysts of the present invention are activated, before use, by sulfidation according to the known methods.

For example the sulfidation process can be effected in a reducing atmosphere of H 2

S/H

2 at a temperature of 300-500 0 C or 10 by treatment with carbon sulfide in a reducing atmosphere again at 300-500 0

C.

e Example 1 Preparation of catalyst A 2 g of aluminum isopropylate are dissolved at room tem- 15 perature in 68.5 g of aqueous solution of tetrapropylammonium hydroxide (TPA-OH at 13.35% by weight). The solution is heated to 60 0 C and 104.1 g of tetraethylsilicate (TES) are added. The resulting mixture has the following ratios: e* SiO 2 /A1203 102, TPA-OH/SiO 2 0.09 On maintaining this mixture under stirring at 60 0 C for minutes, a homogeneous gel is formed which is dried in a stream of air at 90 0 C and then calcined at 550 0 C in a stream of nitrogen for 3 hours and subsequently a stream of air for a further 10 hours at the same temperature. A silica and alumina gel carrier is obtained, which is amorphous to 12 X-rays, with a quantitative yield with respect to the materials initially charged, with a pore diameter ranging from to 40 A, a porosity of 0.47 ml/g.

The gel thus obtained is bound with pseudobohemite, the latter in a quantity of 39% by weight with respect to the total weight of the calcined silica and alumina gel plus the ligand, extruded into cylindrical pellets and ground (40-70 mesh, Asup 660 m 2 10 g of the material thus obtained *o° are then impregnated with 25 ml of aqueous solution contain- 10 ing 10.3 g of (NH 4 6 Mo 7 0 24 4H20 (Ammonium heptamoldibdate, hereafter called EMA) and left to rest at room temperature for 20 hours. The mixture is then dried in an oven in air at 1100C for 2 hours. The dried product is subsequently impregnated with 12 ml of aqueous solution containing 1.17 g of 15 Co(NO 3 6H20 (Cobalt nitrate, hereafter called CoN), the whole mixture being left to rest at room temperature for hours. It is then dried in an oven in air at 1100C for hours and calcined at 500 0 C for 4 hours, in air (rising rate: 180 0 C/hour). The chemical analysis of catalyst A relating to the metal content is indicated in Table 1.

Example 2 Preparation of catalyst Al 2 g of aluminum isopropylate are dissolved at room temperature in 68.5 g of aqueous solution of tetrapropylammonium hydroxide (TPA-OH at 13.35% by weight). The solution is 13 heated to 60 0 C and 104.1 g of tetraethylsilicate (TES) are added. The resulting mixture has the following ratios: SiO 2 /A1 2 03 102, TPA-OH/SiO 2 0.09 The temperature is maintained at 60-650C until a mixture A having a viscosity of 0.011 Pa sec, is obtained. This mixture, after aging at room temperature for 20 hours, is put in a mixer and pseudobohemite Versal 150 (La Roche) in a quantity of 39% by weight with respect to the end weight of extruded silica and alumina gel, component a)with ligand, and 2.16 g of methylcellulose (Methocel Fluka 64625), are added, under mixing. After about an hour of mixing 0.26 g of glacial acetic acid are added and the temperature of the paste-mixer jacket is brought to about 50-60 0 C. The mixing is containing under heating until a homogeneous paste having 15 a consistency suitable for extrusion, is obtained. At the end of the extrusion, aging is carried out for a night at room temperature, followed by drying at 1000C for 5 hours and calcination at 550 0 C for 8 hours in air. 10 g of the extruded silica and alumina gel, component a) with ligand thus obtained are then impregnated with 25 ml of an aqueous solution containing 10.3 g of (NH 4 Mo 7 0 24 4H 2 0 (Ammonium heptamoldibdate, hereafter called EMA) and left to rest at room temperature for 20 hours. The mixture is then dried in an oven in air at 110 0 C for 2 hours. The dried product is subsequently impregnated with 12 ml of aqueous solution con- 14 taining 1.17 g of Co(N0 3 2 6H 2 0 (Cobalt nitrate, hereafter called CoN), the whole mixture being left to rest at room temperature for 20 hours. It is then dried in an oven in air at 110°C for 1.5 hours and calcined at 500°C for 4 hours, in air (rising rate: 180°C/hour). The chemical analysis of catalyst Al relating to the metal content is the same as that for catalyst A.

S. Example 3 Preparation of catalyst B :10 10 g of the silica and alumina gel prepared, extruded and ground as described in example 1 are impregnated with 22 ml of aqueous solution containing 3.5 g of EMA and left to rest at room temperature for 20 hours. The mixture is then dried in an oven in air at 1000°C, for 2 hours. The dried 15 product is subsequently impregnated with 12 ml of aqueous solution containing 2.46 g of CoN, the whole mixture being left to rest at room temperature for 23 hours. It is then dried in an oven in air at 100°C for 6 hours and calcined at 5500°C for 4 hours, in air (rising rate: 180°C/hour) The chemical analysis of the catalyst relating to the metal content is indicated in Table 1.

Example 4 Preparation of catalyst C 13.3 g of the silica and alumina gel prepared, extruded and ground as described in example 1 are impregnated with 15 29.2 ml of aqueous solution containing 2.5 g of EMA and left to rest at room temperature for 18 hours. The mixture is then dried in an oven in air at 1000C,. for 2 hours. The dried product is subsequently impregnated with 29.2 ml of aqueous solution containing 1.75 g of CoN, the whole mixture being left to rest at room temperature for 20 hours. It is then dried in an oven in air at 100°C for 2 hours and calcined at 550 0 C for 4 hours, in air (rising rate: 180°C/hour). The chemical analysis of the catalyst relating 10 to the metal content is indicated in Table 1.

Example Preparation of catalyst D The same procedure is adopted as in example 4, but using an acid silica and alumina gel carrier with a ratio 15 Si0 2 /A1 2 03 204, extruded but not ground. This carrier is prepared as described in example 1 using a quantity of TES equal to 208.2 g.

Example 6 Preparation of catalyst E The same procedure is adopted as in example 5, except that the silica and alumina gel carrier is ground after extrusion to 40-70 mesh.

Example 7 Comparative catalyst F A commercial catalyst is used, containing cobalt and 16 molybdenum impregnated on y-alumina. The chemical analysis of the catalyst relating to the metal content is indicated in Table 1.

Example 7a Preparation of catalyst G comparative A comparative catalyst is prepared by introducing cobalt and molybdenum during the synthesis of the acid silica and alumina gel carrier as described in EP 748652.

3.3 g of CoN are dissolved in 47.48 g of BuOH, under continuous stirring at 60 0 C for 15 minutes; 1.0 g of Si(OC 2

H

5 4 (tetraethylorthosilicate, TES) and 25.1 g of Al(OC 4 H9) 3 (aluminum sec-butoxide) are then added, and the stirring continued at 600C, for 15 minutes. Suspension G1 is obtained.

15 3.2 g of EMA are dissolved in 33.0 g of (C 3

H

7 4 NOH (Tetrapropylammonium hydroxide, solution at 19.2%) at room temperature, obtaining solution G2).

Solution G2)is poured into suspension Gl), under stirring, at 80°C, these conditions being maintained for 1 h.

This is followed by aging at room temperature for 16 h, drying in a vacuum oven at 1000C for 6 h, and calcination in muffle according to the following temperature program: heating to 2000C (5 0 C/min); pause at 2000C for 2 h; heating to 550°C (5 0 C/min); pause at 5500C for 3 h; spontaneous cooling to room temperature.

17 a0 a Table 1 summarizes the physico-chemical characteristics and chemical analysis for catalysts A-E according to the process of the present invention and for comparative catalysts F and G.

In particular the chemical analysis relates to the metal content expressed as weight percentage of Co and Mo and as their molar ratio: Table 1 Catal. Co/Mo Mo(wt Co (wt Asup (m 2 /g) A 0.069 44.2 1.9 310 B 0.37 16.0 3.6 260 C 0.35 10.7 2.3 370 D 0.45 8.2 2.2 370 E 0.45 8.3 2.3 440 F 0.43 12.0 3.2 245 G 0.61 18.1 6.8 430 Tests on model charge The performances of catalysts B, C and E are provided hereunder, obtained using the so-called "model charge" as feed, which represents the typical composition of FCC gasoline, in terms of S content and percentage of olefins. The 18 model charge consists of: 30 wt of 1-pentene; 0.25 wt of thiophene, equal to about 1000 ppm S; the complement to 100 is n-hexane.

The operating conditions are selected so as to obtain conversions higher than 90% (as HDS) and are kept relatively bland (250 0 C T 300 0 H2 is fed at PH2 10 bars.

The parameters selected for evaluating the catalytic activity are: 10 HDS conversion equal to 100 x (ppm Sin-ppm Sout)/Sin; ISO isomerizing activity equal to 100 x (i-pentanes i-pentenes)/SUM Cs; -HYD hydrogenating activity equal to .o 15 100 x n-pentaneout/1 pentenei,; -HDS/HYD ratio, measurement of the selectivity of the catalyst towards desulfuration; -HYD/ISO ratio, inversely proportional to the selectivity towards branched products.

The catalysts are all activated with the same procedure in a stream of H 2

S/H

2 Example 8 Activity of catalyst B 2 g of catalyst B prepared according to example 3, diluted with corindone, are charged into a reactor (40-70 19 mesh) and activated by a stream of the mixture H 2

S/H

2 vol H 2 at 4000C, for 3 hours; the system is then brought under a pressure of H 2 up to 10 bars, with T 2500C. The model charge is sent to the catalytic bed, with a ratio

H

2 /hydrocarbon charge of 300N1/1. The operating conditions and catalytic results are indicated in Table 2.

Table 2 T(OC) WHSV HDS% ISO% HYD% HDS/HYD HYD/ISO S 10 (h- 1 286 4.06 96.7 37.4 38.3 2.5 288 6.23 94.4 26.4 38.3 2.5 1.4 269 4.06 89.9 21.5 34.1 2.6 1.6 Example 9 Activity of catalyst C 2 g of catalyst C prepared according to example 4, diluted with corindone, are charged into a reactor (40-70 mesh) and activated by a stream of the mixture H 2

S/H

2 vol H 2 at 4000C, for 3 hours; the system is then brought under a pressure of H 2 up to 10 bars, with T 2500C. The model charge is sent to the catalytic bed, with a ratio H2/hydrocarbon charge of 300N1/1. The operating conditions and catalytic results are indicated in Table 3.

20 Table 3 T(OC) WHSV HDS% ISO% HYD% HDS/HYD HYD/ISO (h- 1 287 6.12 96.3 43.1 30.5 3.2 0.7 271 4.21 94.1 36.1 30.2 3.1 0.8 287 4.21 96.6 34.6 43.1 2.2 1.2 Example Activity of catalyst E 2 g of catalyst E prepared according to example 6, diluted with corindone, are charged into a reactor (40-70 mesh) and activated by a stream of the mixture H 2

S/H

2 a 15 vol H 2 at 4000C, for 3 hours; the system is then brought under a pressure of H2 up to 10 bars, with T 2500C. The model charge is sent to the catalytic bed, with a ratio

H

2 /hydrocarbon charge of 300N1/1. The operating conditions and catalytic results are indicated in Table 4.

21 Table 4 T(oC) WHSV HDS% ISO% HYD% HDS/HYD HYD/ISO (h- 1 287 4.1 98.2 30.1 50.9 1.9 1.7 288 6.1 96.8 26.3 45.3 2.1 1.7 270 4.1 93.3 17.8 44.7 2.1 09o 9 Example 11 Activity of catalyst F comparative 2 g of catalyst F prepared according to example 7, di- *999 luted with corindone, are charged into a reactor (40-70 mesh) and activated by a stream of the mixture H 2

S/H

2 vol H 2 at 400°C, for 3 hours; the system is then brought under a pressure of H 2 up to 10 bars, with T 250 0 C. The model charge is sent to the catalytic bed, with a ratio

H

2 /hydrocarbon charge of 300N1/1. The operating conditions and catalytic results are indicated in Table 22 Table T(oC) WHSV HDS% ISO% HYD% HDS/HYD HYD/ISO (h- 1 250 4.0 89.7 2.5 37.4 2.4 15.0 270 4.0 100.0 2.6 80.6 1.2 31.0 Example 12

S*

S Activity of catalyst G comparative 2 g of catalyst F prepared according to example 7a, diluted with corindone, are charged into a reactor (40-70 mesh) and activated by a stream of the mixture H 2

S/H

2 vol H 2 at 400 0 C, for 3 hours; the system is then brought 15 under a pressure of H 2 up to 10 bars, with T 250 0 C. The model charge is sent to the catalytic bed, with a ratio

H

2 /hydrocarbon charge of 300N1/1. The operating conditions and catalytic results are indicated in Table 6.

Table 6 T(OC) WHSV HDS% ISO% HYD% HDS/HYD HYD/ISO (h- 1 293 3.9 91.5 0.8 86.0 1.1 107.5 274 3.9 92.1 0.7 89.9 1.0 128.4 23 These tables demonstrate the greater isomerizing activity of the catalysts of the present invention C and E), both in absolute terms (ISO%) and relating to the hydrogenating capacity (HYD/ISO).

A similar comparison between the formulations B, C and E, on the one hand, and F and G on the other, can be based on the respective performances under the same operating conditions (WHSV 4 hours-'; T 270 0 C, as indicated in Table 7).

10 Table 7 .e Catalyst HDS ISO HDS/HYD HYD/ISO SB 89.9 21.0 2.6 1.6 C 94.1 36.1 3.1 0.8 E 93.3 17.8 2.1 F 100.0 2.6 1.2 31.0 G 92.1 0.7 1.0 128.4 From this comparison it can be seen that, with the same operating conditions, the catalysts of the present invention C and E) have a higher isomerizing activity (more than an order of magnitude) and also a lower hydrogenating activity (lower HYD/ISO ratio), with respect to the comparative 24 catalysts.

In particular the best performances are obtained with catalyst C having a composition corresponding to a ratio SiO 2 /A1 2 0 3 100 and a molybdenum content of 10.6%. This is confirmed by the data at T 288 0 C and WHSV 6.1 hours (Table 8).

Table 8 Catalyst HDS ISO HDS/HYD HYD/ISO .10 10 B 94.4 26.4 2.5 1.4 C 96.3 43.1 3.2 0.7 E 96.8 26.3 2.1 1.7 *o Tests on FCC Full Range Naphtha Some examples are provided hereunder of performances of catalysts of the present invention, evaluated on FCC Full Range gasoline, characterized by the following composition: Table 9 S Paraff. Naphthenes olefins Cyclo- aromatics RON MON (ppm) olefins 200°C 16- 1360 20.4 9.4 30.3 5.6 24.8 8.9 93.3 80.7 25 wherein S ppm is the sulfur content and columns two to six indicate the volume percentage of normal and iso paraffins, naphthenes, normal and iso olefins, cyclo-olefins, aromatics, respectively. The last column indicates the volume percentage of the fraction which boil at over 200 0

C.

Example 13 Activity of catalyst B 2 g of catalyst B prepared according to example 3, diluted with corindone, are charged into a reactor (40-70 10 mesh) and activated in the presence of a mixture of H 2

S/H

2 vol H 2 up to 400 0 C, for 3 hours; the system is then brought under a pressure of H 2 up to 10 bars, sending the eo feed consisting of FCC Full Range gasoline having the composition of Table 9, onto the catalyst with a ratio

H

2 /hydrocarbon charge of 300N1/1 and WHSV of 4 hours The *o operating conditions and catalytic results are indicated in Table Table S Paraff. Naphthenes Olefins Aromatics RON MON (ppm) 200°C 501 272 26.3 9.8 24.8 25.1 9.4 92.4 81.2 277 288 29.2 10.5 21.6 24.8 9.5 91.0 80.3 127 304 33.3 11.2 18.7 24.4 9.5 90.1 80.2 26 Example 14 Activity of catalyst C 2 g of catalyst C prepared according to example 4, diluted with corindone, are charged into a reactor (40-70 mesh) and activated in the presence of a mixture of H 2

S/H

2 vol H2), up to 400 0 C, for 3 hours; the system is then brought under a pressure of H 2 up to 10 bars, sending the feed consisting of FCC Full Range gasoline (see Table 9), onto the catalyst with a ratio H2/hydrocarbon charge of 10 300N1/1 and WHSV 4.4 h The operating conditions and catalytic results are indicated in Table 11.

Table 11 S Paraff. Naphthenes Olefins Aromatics RON MON (ppm) 200°C 538 252 24.6 9.6 26.8 24.8 9.5 81.0 224 272 26.2 9.9 24.8 24.9 9.7 91.7 80.9 115 287 27.8 10.4 22.8 25.0 10.0 91.5 80.7 Example Activity of catalyst F comparative 2 g of catalyst F prepared according to example 7, diluted with corindone, are charged into a reactor (40-70 27 mesh) and activated in the presence of a mixture of H 2

S/H

2 vol H 2 up to 400 0 C, for 3 hours; the system is then brought under a pressure of H 2 up to 10 bars, sending the feed consisting of FCC Full Range gasoline (see Table 9), onto the catalyst, with a ratio H2/hydrocarbon charge of 300N1/1 and WHSV 4 h- 1 The operating conditions and catalytic results of the gasoline thus obtained are indicated in Table 12.

Table 12 10 w S T(OC) Paraff. Naphthenes Olefins Aromatics RON MON o o (ppm) 200 0

C

886 230 22.8 10.0 27.8 23.3 10.4 92.3 80.3 551 248 24.2 10.3 26.5 23.2 10.2 91.8 80.2 158 269 28.6 11.3 21.7 23.4 9.7 89.3 79.3 Table 13 compares the variations in the octane qualities of the products obtained with catalysts B, C and F, at 90% of HDS conversion. The catalysts of the present invention (B and C) have a lower loss, in terms of both RON and MON, with respect to F; catalyst C is, in particular, the one which ensures the lowest loss.

28 Table 13 Catalyst

ARON

AMON

ARON+MON/2) -3.2 -1.8 -0.5 0 -1.4 -1.85 -0.9 -2.7 Throughout the description and claims of this specification, use of the word "comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps.

The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of this application.

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